Hinge clamp

ABSTRACT

A hinge clamp for releasably and hingably attaching a bar to a support. The clamp has a pair of angle brackets whose interior corners open toward one another to define between the brackets an effective opening for receiving the bar endwise in a manner such that the bar is cradled between the flanges of each bracket. A mounting plate hinged to one bracket on a hinge axis parallel to the axis of the opening, and clamp means for urging the brackets toward one another to firmly and positively grip the bar. A primary application of the hinge clamp is attaching a silk screen frame to a frame support.

United States Patent Kaino J Hamu [72] Inventor 4013 North Durt'ee Ave., El Monte, Calif. 91732 [21] App1.No. 878,157 [22] Filed Nov. 19, 1969 [45] Patented Sept. 28, 1971 [54] HINGE CLAMP 4 Claims, 3 Drawing Figs.

[52] US. Cl 248/316 A, 16/129, 24/263 A, 248/226 B [51] Int. Cl E05d 7/04 [50] Field of Search 248/226 R, 226 A, 226 B, 316R, 316A, 316 B; 21 1/48,99; 24/263 A, 263 R; 16/158, 129

[56] References Cited UNITED STATES PATENTS 1017.153 2/1912 Kampe 248/226X Primary Examiner-J. Franklin Foss Attorney-Boniard 1, Brown ABSTRACT: A hinge clamp for releasably and hingably attaching a bar to a support. The clamp has a pair of angle brackets whose interior corners open toward one another to define between the brackets an effective opening for receiving the bar endwise in a manner such that the bar is cradled between the flanges of each bracket. A mounting plate hinged to one bracket on a hinge axis parallel to the axis of the opening, and clamp means for urging the brackets toward one another to firmly and positively grip the bar. A primary application of the hinge clamp is attaching a silk screen frame to a frame support.

PATENTED SEP28 I971 M/l/EA/TOR KA/A/o J. HAMU A TTOEA/EV HINGE CLAMP BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to hinge devices and more particularly to a novel hinge clamp for releaseably and hingably attaching a bar to a support.

2. Prior Art As will appear from the ensuing description, the present hinge clamp is capable of a variety of uses. However, the principal application of the clamp is in the silk screen printing art for releaseably and hingably attaching a silk screen frame to a frame support. The invention will be described in connection with this particular use.

The silk screen printing process involves the use of printing screen mounted in a rectangular screen frame. This frame has side frame members, or frame bars as they are referred to in this disclosure, which carry means for gripping the screen about its edge and biaxially stretching the screen in its edgewise direction. The actual silk screen printing process is well known and need not be explained. Suffice it to say that in the course of the printing process, it is necessary to attach the screen frame to a frame support in a manner such that the frame may hinge relative to the support and be readily removed from and remounted on the support. To this end, one frame bar of the screen frame is attached to the support by one or more so-called hinge clamps.

A hinge clamp, as its name implies, is essentially a combined hinge and clamp. A variety of such hinge clamps have been devised. While the existing clamps differ in their detailed construction, they are all characterized by a clamp bracket for seating a frame bar of a screen frame, a mounting plate hinged to the bracket and adapted for attachment to the frame support, and clamp means, such as clamp screws for clamping the frame bar to the bracket. The arrangement of the hinge clamps is such that the screen frame may be quickly and easily removed from and remounted in a clamp by simply releasing the clamp screws.

The existing hinge clamps, while satisfactory to a degree, have a disadvantage which this invention overcomes. This disadvantage resides in the fact that the clamping means or clamp screws of the existing hinge clamps effectively exert only a frictional gripping action rather than a positive gripping action on the screen frame bar engaged by the clamping means. As a consequence, the frame bar often tends to slip in the clamp. Because of this type of gripping action, the existing hinge clamps cause rapid wear, marring, and other deterioration of screen frames which are commonly constructed of wood.

SUMMARY OF THE INVENTION The present invention avoids the above and other disadvantages of the existing hinge clamps. To this end, the invention provides an improved hinge clamp having a pair of angle brackets whose interior corners open toward one another to define between the brackets an effective opening for receiving a silk screen frame bar in a manner such that the bar is cradled between the flanges of each bracket. A mounting plate hinged to one bracket on a hinge axis parallel to the axis of the opening, and clamp means for urging the brackets toward one another to firmly and positively grip the bar. In the particular inventive embodiment disclosed, the flanges of each clamp bracket are generally perpendicular to one another and parallel to the hinge axis. The two brackets seat diagonally opposed longitudinal corner portions of the bar. The clamping means of the hinge clamp comprise a pair of clamp screws carried by and extending normal to the flanges, respectively, of the fixed bracket, that is the bracket which is hinged to the mounting plate. One screw is fixed to the other, adjustable bracket and is longitudinally adjustable to move the latter bracket toward and away from the fixed bracket flange mounting the screw. The other screw seats against the adjustable bracket and is longitudinally adjustable to move the latter bracket toward and away from the other flange of the fixed bracket.

When installing a screen frame in the hinge bracket, the clamp screws are retracted to permit placement of one frame bar between the clamp brackets. The clamp screws are then tightened to firmly and positively clamp or grip the frame bar between the brackets. The screen frame is removed by reversing the procedure. When the frame is installed in the hinge clamp, the frame is rotatable about the clamp hinge axis relative to the frame support to which the clamp mounting plate is fixed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a screen frame attached to a frame support by a pair of the present hinge brackets;

FIG. 2 is an enlarged section taken on line 22 in FIG. I; and

FIG. 3 is an enlarged perspective view of one of the hinge clamps in FIG. ll.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 illustrates a silk screen frame: 10, a frame support 112, and a pair of the present hinge clamps 14 which mount the frame on the support hinging movement about a hinge axis 16 parallel to one frame bar 18 of the frame. In this instance, the support 12 is a platen for receiving a work sheet to be printed in printing position below a silk screen 20 attached about its edges to the frame. As noted earlier, a typical screen frame is provided with means for gripping the silk screen about its edges and biaxially stretching the screen. These gripping and tensioning means have been omitted for the sake of convenience. The hinge clamps 14 permit swinging of the frame and its screen 20 toward and away from the platen 12 for placement of a work sheet in and removal of the sheet from printing position.

Referring now to FIGS. 2 and 3, the hinge clamp 14 will be seen to comprise a pair of angle brackets 22 and 24 having mutually perpendicular flanges 26 and 28, respectively. The flanges of each bracket define an interior corner 30. Brackets 22 and 24 are disposed with their interior corners opening toward one another in a manner such that the brackets have a first pair of flanges in spaced generally parallel planes and a second pair of flanges in spaced generally parallel planes normal to the planes of the first flanges. The two brackets thus define a generally rectangular frame bar receiving opening 32 having an axis extending normal to the paper in FIG. 2.

Hinge clamp 14 also has a mounting plate 34 to be secured, in any convenient manner, to the platen 12. Mounting plate 34 is attached by hinge means 36 to the clamp bracket 22, hereafter referred to as the fixed bracket, for hinging movement of the latter bracket relative to the mounting plate on the hinge axis 16. Hinge axis 16 parallels the bracket flanges 26, 28 and hence the axis of the bar receiving opening 32. The hinge axis is located a small distance above the undersurfaces of the lower fixed bracket flange and the mounting plate, as the hinge clamp is viewed in FIG. 2.

Hinge clamp 14 is equipped with clamping means 38 for moving the clamp bracket 24, hereafter referred to as the adjustable bracket, toward and away from the fixed bracket 22. The illustrated clamping means 38 comprises a first clamp screw 40 which extends through a longitudinal slot 42 in the upstanding flange 26 of the fixed bracket 22 in FIG. 2. Threaded on this clamp screw outboard of the flange is a wing nut 44. The inner or left-hand end of screw 40 is welded or otherwise secured to the upper flange 28 of bracket 24. The axis of the screw parallels the plane of its attached flange and, in this instance, lies in the plane of the flange. Clamping means 38 comprises a second clamp screw 46 which is threaded in an upper inturned extremity 48 of the upstanding fixed bracket flange 26 which has the clamp screw slot 42. The lower end of clamp screw 46 seats against the upper flange 28 of the adjustable clamp bracket 24. Threaded on the clamp screw 48 above the latter flange is a jam nut 50. v

In use, the mounting plates 34 of the hinge clamps 14 are secured to the platen 12 in positions such that hinge axes 16 of the two clamps coincide. The spacing between the clamps is somewhat less than the length of the screen frame bar 18 measured within the frame opening. The frame is installed in the hinge clamps 14 by adjusting the clamp screws 40, 46 in directions to retract the adjustable clamp brackets 24 away from the fixed clamp brackets 22 sufficiently to enable the frame bar 18 to be inserted into the hinge clamp openings 32. The clamp screws are then adjusted in the opposite directions to move the adjustable brackets toward the fixed brackets to their clamping positions of FIG. 2. In these clamping positions, the frame bar 18 is firmly and positively clamped or gripped between the respective fixed and adjustable clamp brackets. The brackets then straddle the frame bar in a transverse diagonal direction of the bar, such that diagonally opposed longitudinal comer portions of the bar are effectively cradled in their interior bracket corner 30 and between their respective flanges 26, 28. Removal of the screen frame 10 from the hinge clamps 14 is accomplished by reversing the above procedure. Since the screen frame bar 18 is firmly and positively gripped by and between the clamp brackets 22, 24, there is no possibility of slippage of the bar relative to the hinge clamps. Accordingly, the hinge clamps do not tend to mar or otherwise destroy the screen frame.

The inventor claims:

1. A clamp for releaseably attaching a bar to a support comprising:

a pair of angle brackets having interior corners opening diagonally toward one another to define between the brackets an effective generally rectangular opening for receiving said bar endwise in a manner such that the bar is cradled between the flanges of each bracket,

said opening having an axis parallel to said bracket flanges,

and

two separate clamp screws engaging the other bracket for moving the other bracket toward and away from said one bracket independently along two mutually perpendicular direction lines parallel to the sides, respectively, of said opening to firmly and positively grip said bar between said brackets and release said bar for removal from said hinge clamp.

2. A hinge clamp according to claim 1 wherein:

the flanges of each bracket are mutually perpendicular, and

said brackets have first flanges in spaced parallel planes and second flanges in spaced parallel planes normal to the planes of said first flanges. i

3. A hinge clamp according to claim 2 wherein:

said clamp screws comprise a first clamp screw connected between said brackets for moving said other bracket in a direction parallel to one of its flanges, and a second clamp screw acting between said brackets for moving said other bracket in a direction parallel to its other flange.

4. A hinge clamp according to claim 3 wherein:

said first clamp screw parallels and is secured to said one flange of said other bracket and extends through a longitudinal slot in the mutually perpendicular flange of said one bracket, and said second clamp screw is threaded in the latter flange on an axes perpendicular to said one flange of said other bracket and seats against the latter flange. 

1. A clamp for releaseably attaching a bar to a support comprising: a pair of angle brackets having interior corners opening diagonally toward one another to define between the brackets an effective generally rectangular opening for receiving said bar endwise in a manner such that the bar is cradled between the flanges of each bracket, said opening having an axis parallel to said bracket flanges, and two separate clamp screws engaging the other bracket for moving the other bracket toward and away from said one bracket independently along two mutually perpendicular direction lines parallel to the sides, respectively, of said opening to firmly and positively grip said bar between said brackets and release said bar for removal from said hinge clamp.
 2. A hinge clamp according to claim 1 wherein: the flanges of each bracket are mutually perpendicular, and said brackets have first flanges in spaced parallel planes and second flanges in spaced parallel planes normal to the planes of said first flanges.
 3. A hinge clamp according to claim 2 wherein: said clamp screws comprise a first clamp screw connected between said brackets for moving said other bracket in a direction parallel to one of its flanges, and a second clamp screw acting between said brackets for moving said other bracket in a direction parallel to its other flange.
 4. A hinge clamp according to claim 3 wherein: said first clamp screw parallels and is secured to said one flange of said other bracket and extends through a longitudinal slot in the mutually perpendicular flange of said one bracket, and said second clamp screw is threaded in the latter flange on an axes perpendicular to said one flange of said other bracket and seats against the latter flange. 